        to "[:code "app-state"]". "[:code "log-app-state"]" would
        continue to run until you stop it, using "[:code "(r/dispose!
        logger)"]"."]
+
 
        [:h2 "with-let: Handling destruction"]
 

         [:li [:code "next-tick"]" is now guaranteed to execute its
         argument before the next render (more on that below.)"]]]

       [:h2 "track: Use any function as a reactive value"]

       [:p [:code "reagent.core/track"] " takes a function, and

        trigger warnings due to unexpected return values, and may
        cause severe headaches if an event handler called by dispatch
        itself dispatches a new event (that would result in lost
        events, and much confusion)."]

        [:p "For a more structured version of this approach, see the
        excellent "[:a
        {:href "https://github.com/Day8/re-frame"} "re-frame"]"
        framework."]]

       [:section.demo-text
        [:h2 "New React version and new namespaces"]
